Studies towards the total synthesis of the Martinella and pyrrole-imidazole alkaloids

In Part I, a concise approach to pyrrolo[3,2-c]quinolones is described which relies on an intramolecular azomethine ylide alkene cycloaddition reaction. Critical to the success of this reaction was the requirement for alkylation of the aniline nitrogen. A formal total synthesis of Martinella alkaloids has been accomplished from the cycloadduct, a pyrrolo[3,2- c]quinolone, utilizing a stereoselective addition of a highly functionalized copper acetylide to an in situ generated iminium ion under aqueous conditions.; In Part II, a novel, mild and highly efficient synthetic protocol for the synthesis of spiro-linked cyclopentylimidazolones was developed via a dimethyldioxirane-mediated oxidative rearrangement reaction of tetrahydrobenzimidazoles. Investigation of the feasibility of the similar oxidative rearrangement of tetrahydroimidazo[4,5-b] pyridine derivatives for the construction of spiro-linked pyrroloimidazolone is also described. These reactions could form the basis of approaches to the synthesis of various pyrrole-imidazole alkaloids.; In Part III, intramolecular Diels-Alder reactions of 4-vinylimidazoles with various diene-dienophile linkers were systematically investigated. The synthesis and Diels-Alder reactions of these 4-vinylimidazole derivatives, along with efforts toward the total synthesis of ageliferin are described.; In Part IV, an efficient method for the regioselective protection of 4-alkyl-, 4-iodo-, and 4-vinylimidazoles was established via an alkylation-isomerization sequence with various imidazole-protecting groups. The initially formed mixture of 4/5-alkyl-, 4/5-iodo and 4/5-vinylimidazoles were isomerized to the corresponding 4-isomers on treatment with a small amount of the alkyl halide.*; *This dissertation is multimedia (contains text and other applications not available in printed format). The CD requires the following system requirements: Adobe Acrobat.